A manufacturer of bolts has a quality-control policy that requires it to destroy any bolts that are more than standard deviations from the mean. The quality-control engineer knows that the bolts coming off the assembly line have mean length of cm with a standard deviation of cm. For what lengths will a bolt be destroyed?

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circle area = pi * radius^2

if diameter = 10 then radius = 5

circle area = pi * 5^2

circle area = pi * 25

circle area = 78.5398163397 square units

step-by-step explanation:

for this case we must apply distributive property to the following expression:

the distributive property states that:

then, when applying the property we have to multiply the -2 for each term within the parenthesis: